Aims: Slower heart rate recovery (HRR) following exercise is associated with the metabolic syndrome, yet the temporal relationship between the two remains unknown. We investigated the cross-sectional and longitudinal associations of slower HRR following a graded exercise treadmill test (GXT) with metabolic syndrome components and LDL-C. Methods and results: Participants aged 18-30 from the Coronary Artery Risk Development in Young Adults study underwent a symptom-limited maximal GXT at baseline (n=4319) and 7 years later. HRR was calculated as the difference between maximum heart rate (HR) and HR 2 min after test cessation. Slower baseline HRR was associated with a higher cross-sectional level but not longitudinal (15 year follow-up) increases in blood pressure, triglyceride, waist circumference, and LDL-C. No cross-sectional or longitudinal association was observed between HRR and HDL-C. In contrast, participants with one or two or more metabolic syndrome components (National Cholesterol Education Program III and American Diabetes Association criterion) at baseline examination had significantly larger longitudinal declines in HRR [-3.48 (P<0.05) and-5.64 bpm (P<0.001), respectively] from baseline to year 7, when compared with participants without syndrome components (-2.40 bpm). Conclusion: Slower HRR does not precede development of the metabolic syndrome, but appears after syndrome components are present.
Bibliographical noteFunding Information:
M.A.K. was supported by a National Research Service Award, NIH/ NHLBI post-doctoral training fellowship (T32 HL069771). M.R.C. was supported in part by a career development award from the NHLBI/NIH (5 KO1 HL73249-03). CARDIA was supported by grants and contracts from the NHLBI (N01-HC-48047, N01-HC-48048, N01-HC-48049, N01-HC-48050, N01-HC-95095).
- Autonomic nervous system
- Coronary risk factors
- Exercise treadmill
- Heart rate recovery
- Insulin resistance
- Metabolic syndrome